After weeks of negotiations, a plan to tighten security along America's border with Mexico got bipartisan support in Congress Thursday.

Senate lawmakers agreed to amend a bill that includes the spending of tens of billions of dollars on enhanced border security measures in exchange for immigration reform that does not delay legalization for illegal immigrants.

"Once the Senate adopts our amendment, I will be proud to vote for a bill that secures our border and respects our heritage as an immigrant nation," Sen. Mark Kirk, R-Ill., said in a statement.

Is this measure a true bi-partisan measure? And why is border security such an important aspect of the deal? Alvaro Vargas Llosa, senior fellow at the Independent Institute and author of the book Global Crossings answers these questions and more, on CBN Newswatch, June 20., following this report.

For Republican lawmakers, increased security was the deal breaker in supporting a Senate immigration bill.

"We don't have control of our southwestern border," Sen. John Comyn, R-Texas.

Some of the key provisions in the legislation include:

A so-called "surge," placing 20,000 new federal agents along the U.S. southern border.

Adding 700 more miles of fence along the U.S.-Mexico border

Buying new surveillance drones to track illegal border crossing.

The bill would come at a price tag of some $30 billion over a decade.

For Democratic lawmakers making a pathway for undocumented immigrants to get U.S. citizenship was key.

"These 11 million people play a crucial part in our economy and a vital role in our communities and they need a pathway to get right with the law," Senate Majority Leader Harry Reid argued.

Under the compromise, immigrants living in the United States illegally would be put on a pathway to citizenship as the added security is implemented. But green cards would not be handed out until the work is complete.

The so-called "Gang of Eight" senators involved in the negotiations are hoping the new security measures will persuade skeptical Republican lawmakers to pass the bill before it heads to the House.

On Tuesday, Speaker of the House John Boehner said it will take some bipartisanship for the Senate immigration bill to pass.

"Any immigration reform bill that is going to go into law ought to have a majority of both parties' support if we're really serious about making that happen," he said.